Mixing ball



FIG. 1 is a top perspective view of a mixing ball;

FIG. 2 is a top side perspective view of the mixing ball;

FIG. 3 is a front view of the mixing ball;

FIG. 4 is a rear view of the mixing ball;

FIG. 5 is a top view of the mixing ball;

FIG. 6 is a right side view of the mixing ball; and,

FIG. 7 is a left side view of the mixing ball.

The broken lines represent portions of the mixing ball that form no part of the claimed design. 

CLAIM The ornamental design for a mixing ball, as shown and described. 